BILLINGS, Mont. — The cleanup of a major oil spill in the Yellowstone River has proven more difficult than expected and could go on for several more months, an Exxon Mobil Pipeline Co. executive said Thursday.
Areas hit hardest by the July spill should be cleaned up by the first half of October, company vice president Geoff Craft said. That includes a 20-mile stretch of the Yellowstone stretching from the spill site near Laurel downstream to Billings. But scattered sites still would need to be dealt with, including contaminated river sections downstream of Billings and two large islands in the heavily impacted area. Work in those areas could continue until Thanksgiving, Craft said.
Slowing the cleanup effort has been the painstaking task of removing crude from hundreds of debris piles deposited by the same spring floodwaters that are widely believed to have triggered the 12-inch pipeline’s failure. Also, the energy company did not want to bring in more workers than necessary to avoid trampling the riverbank, Craft said.
“Nobody would have guessed how hard it would be,” Craft said. “We don’t want to do more harm than good by bringing in too many people or too many vehicles. ... It’s very labor intensive.” Within days of the 1,000-barrel spill, Exxon Mobil was ordered by the Environmental Protection Agency to complete its remediation work by Sept 9. But officials said Thursday that date was not intended as a hard deadline.
EDIT
http://www.washingtonpost.com/national/environment/exxon-mobil-says-efforts-to-clean-up-yellowstone-river-after-oil-spill-will-last-into-fall/2011/08/18/gIQArXB5NJ_story.html